DIN 17175 Heat-resistant Seamless Steel Pipe

DIN 17175 is the technical specification for heat-resistant seamless steel pipes & tubes in the German industrial standard, which is specifically suitable for boilers, pressure vessels and piping systems under high temperature and high pressure environments. The DIN 17175 standard refers to international standards and is adjusted according to the specific needs of Germany, with high technical requirements.

Scope of application:
Seamless steel pipes suitable for manufacturing steam boilers, high-temperature pipelines, pressure vessels and other equipment, with an operating temperature of up to 600°C (some steel grades can withstand high temperature loads for a long time).

The steel pipes covered must meet the requirements of heat resistance, high temperature strength and oxidation resistance.

Replacement relationship:
Replaced the old version of DIN 17175 (Part 1 and Part 2) and is associated with the international standard ISO 2604Ⅱ.

Main steel types and characteristics:

DIN 17175 includes a variety of heat-resistant steels, typical grades include:

Grade	Characteristics	Applicable temperature/pressure	Corresponding international standards
St35.8	Low carbon steel, used in low temperature and low pressure environment	≤500℃, medium and low pressure boilers	China GB 8163 (20# steel)
ST45.8	Low carbon steel, used in medium and high temperature and high pressure environment	≤500℃, can withstand 550℃ for a short time	China GB 5310 (20G)/ASME SA106B
15Mo3	Molybdenum-containing alloy steel, good creep resistance	450~550℃, medium pressure boiler	ASME SA-210
13CrMo44	Chromium-molybdenum steel, resistant to high temperature oxidation and corrosion	550~600℃, high pressure boiler	EN 10216-2
10CrMo910	High chromium molybdenum steel, pipe for supercritical unit	600~650℃, ultra-high pressure boiler	ASME SA-335 P22

Manufacturing process:
Heat-resistant seamless steel pipes are usually produced by hot rolling, cold drawing, hot expansion and other methods, and need to be delivered in a heat-treated state (such as normalizing).

Performance requirements:

1. Mechanical properties: Steel pipes of different grades have different tensile strength, yield strength and elongation requirements. For example, the tensile strength of St35.8 is 360~480MPa, the yield strength is ≥235MPa, and the elongation is ≥25%; the tensile strength of St45.8 is 410~530MPa, the yield strength is ≥255MPa, and the elongation is ≥21%‌.

2. Chemical composition: strictly control the content of elements such as C, Cr, and Mo. For example, the Cr content of 13CrMo44 is 0.7~1.10%, and the Mo content is 0.45~0.65%.

3. Surface quality: no cracks, peeling, and folding. Small protrusions, depressions, and shallow longitudinal rolling marks that do not exceed the wall thickness deviation are allowed to exist. Defects can be repaired, but the minimum wall thickness must be guaranteed. The outer diameter is allowed to slightly exceed the negative deviation, but its length should be ≤1m.

Inspection items:
Water pressure test, ultrasonic flaw detection (UT), tensile test, impact test, etc.

Water pressure for each branch or eddy current instead of water pressure.
Water pressure pressure 8MPa, eddy current according to 1925.
Ultrasonic flaw detection of longitudinal defects for each Grade III pipe is carried out according to 1915.

Typical application occasions:

Boiler components: superheater, reheater, main steam pipeline, etc.
Petrochemical and energy: high temperature reactor, heat exchanger pipeline.
Power industry: high temperature and high pressure pipelines for supercritical/ultra-supercritical thermal power units.

Comparison with other standards:

DIN 17175	Chinese standard	American standard (ASME)	European standard (EN)
St35.8	20# (GB 8163)	SA-106	EN 10216-1
15Mo3	15MoG (GB 5310)	SA-209	EN 10216-2
10CrMo910	12Cr2MoG	SA-335 P22	EN 10216-2

DIN 17175 is the authoritative standard for high temperature heat-resistant seamless steel pipes. Its steel grades cover from low carbon steel to high alloy steel, and are suitable for industrial scenarios with different temperature and pressure levels. There is a corresponding relationship with ASME, GB and other standards, but it is necessary to pay attention to the specific composition and performance differences.

Read more: ASTM A335 P11 vs P22 Pipe or ASTM A106 Seamless Carbon Steel Pipe